In two-cycle engines of the type employed in lawn mowers and outboard engines, oil is mixed with gasoline in the appropriate amounts by manually adding a measured quantity of oil to the fuel tank at the time that the gasoline is added to the tank.
As described in the Walworth U.S. Pat. No. 4,381,741, issued May 3, 1983, some two-cycle outboard engines also include two separate containers, one for gasoline and one for oil, and means are also provided for pumping gasoline and oil to the engine where they are mixed in suitable proportions and then fed directly to the combustion chambers of the engine.
Attention is also directed to an apparatus for mixing scale reducing chemicals with water added to a boiler illustrated in the Averill U.S. Pat. No. 1,577,157 issued Mar. 16, 1926.
Attention is further directed to the Houseman et al. U.S. Pat. No. 4,312,595 issued Jan. 26, 1982; the Miller et al. U.S. Pat. No. 3,345,997 issued Oct. 10, 1967 and the British Patent No. 517,635 dated July 31, 1937.